In a recent study we reported an association between very low levels of plasma dopamine-Beta-hydroxylase (D Beta H), values less than or equal to 2MuM/Min/L and the type of psychopathology shown by emotionally disturbed boys. If this finding is confirmed, it will be the closest association yet found between a biochemical measure and a group of symptoms in a non-retarded, emotionally disturbed population of boys. This study attempts to extend our findings using an improved research design, and will also attempt to show that catecholamine metabolism is different in the near zero D Beta H group as compared to those with higher D Beta H activities. Structured diagnostic data and measures of catecholamine metabolism will be obtained on 60 boys with very low D Beta H and a comparison group of at least 60 boys with D Beta H activities of 15MuM/Min/L or greater. Subjects will be children admitted to a children's psychiatric hospital and will be matched by age and I.Q. It is hypothesized that low D Beta H group will have significantly more boys with diagnoses of conduct disorder, undersocialized and borderline personality disorder, and they will have more history of abuse, dangerous aggressive behavior, fire setting and impaired impulse control. The low D Beta H group will have decreased 24 hour urinary excretion of norepinephrine and norepinephrine metabolites, similar or increased epinephrine and metanephrine excretion, and increased dopamine and homovanillic acid excretion. Plasma MHPG will be decreased in the low group and plasma HVA will be increased.